July 14, 2016 - ICP DAS USA introduced the tGW-735i gateway, which adds adds 2500 VDC isolation and expands its communication interfaces. Equipped with 1 Power-over-Ethernet (PoE) port and 3 RS-485 Ports, the tGW-735i allows a Modbus TCP host to communicate with up to 3 serial Modbus RTU/ASCII devices through an Ethernet network, thus saving the cabling costs. The Modbus TCP to RTU gateway can be used to create a pair-connection application (as well as serial-bridge or serial-tunnel application), and can then route data over TCP/IP between two serial Modbus RTU/ASCII devices, which is useful when connecting mainframe computers, servers or other serial devices that use Modbus RTU/ASCII protocols and do not themselves have Ethernet capability.
The read-cache function included in firmware version 1.4.1 is used to store previous requests and responses in the memory buffer. When other HMI/SCADA master controllers send the same requests to the same RTU slave device, the cached response will be returned immediately. This feature reduces the loading time on the RS-485 bus communication, ensures faster TCP responses, and improves the stability of the entire system.
The tGW-735i supports DHCP client function, which allows it to obtain the necessary TCP/IP configuration information from a DHCP server. The tGW-735i is also equipped with a 32-bit MCU to enable efficient handling of network traffic, and a built-in web server that provides a web management interface that allows users to modify the configuration of the module, including the DHCP/Static IP, the gateway/mask settings and the serial port settings.